Mammalian faunal transition in Asia during the Cretaceous: exploring the timing of the first diversification of eutherians

• Project/Area Number: 24740349
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Stratigraphy/Paleontology
• Research Institution: Ehime University
• Principal Investigator: KUSUHASHI Nao 愛媛大学, 理工学研究科, 助教 (70567479)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2013: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2012: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
• Keywords: 哺乳類 / 中生代 / 白亜紀 / 東アジア / 初期進化 / 真獣類 / 進化 / アジア

Outline of Final Research Achievements

To investigate mammalian faunal transition in East Asia during the late Early Cretaceous, when eutherians became a major member of mammalian fauna in Asia, I conducted fossil excavations in Fuxin and neighboring areas, Liaoning, China and taxonomic studies on mammalian fossils from the Shahai and Fuxin formations, Liaoning, China and the Sasayama Group, Hyogo, Japan.
During the course of this project, 120 mammalian fossils were found by the excavations. As excavations of Early Cretaceous mammals, this beyond-expectations result is undoubtedly a big success. Through the taxonomic studies, a few papers describing new mammalian species have been published or accepted for publication, and now a few papers have been submitted and also some papers are in progress for submission. Further investigation on these materials will reveal more precise mode of mammalian faunal transition.

Research Products

• [Journal Article] Two new species of Gobiconodon (Mammalia, Eutriconodonta, Gobiconodontidae) from the Lower Cretaceous Shahai and Fuxin formations, northeastern China (2015)
  • Author(s): Kusuhashi, N., Wang, Y.-Q., Li, C.-K., and Jin, X.
  • Journal Title: Historical Biology Volume: 不明
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] A new Early Cretaceous eutherian mammal from the Sasayama Group, Hyogo, Japan. (2013)
  • Author(s): Kusuhashi, N., Tsutsumi, Y., Saegusa, H., Horie, K., Ikeda, T., Yokoyama, K. and Shiraishi, K.
  • Journal Title: Proceedings of the Royal Society Volume: B 280 (1759) Issue: 1759 Pages: 20130142-20130142
  • DOI: 10.1098/rspb.2013.0142
  • Peer Reviewed
• [Presentation] A mammal jaw from the Upper Cretaceous Ashizawa Formation (Futaba Group), Fukushima, northeastern Japan (2014)
  • Author(s): Kusuhashi, N., Suzuki, T., Terui, K., Sato, A., and Amiot, R.
  • Organizer: 2nd International Symposium of the IGCP 608, Cretaceous Ecosystems and Their Responses to Paleoenvironmental Changes in Asia and the Western Pacific
  • Place of Presentation: 早稲田大学，東京
  • Year and Date: 2014-09-05 – 2014-09-06
• [Presentation] 中国遼寧省の沙海層・阜新層から産出する前期白亜紀哺乳類化石群
  • Author(s): 楠橋 直・王 元青
  • Organizer: 日本古生物学会第162回例会
  • Place of Presentation: 神奈川県横浜市 横浜国立大学